This invention relates to electronic musical instruments and, more particularly, to a technology for designating how a tone generator synthesizes musical tones.
Electronic musical instruments with a tone generator for synthesizing musical tones using a plurality of waveform generation modules are known in the art. Such waveform generator modules can be connected to one another in various forms, and the entirety of the resultant connected structure specifies the way of synthesizing tones.
An electronic musical instrument disclosed in U.S. Pat. No. 4,554,857 (issued on Nov. 26, 1985) incorporates a set of tone synthesis algorithms each defining a connected structure of a plurality of waveform generator modules. Each tone synthesis algorithm has a uniquely assigned numerical value representing the name of the algorithm. A tone synthesis algorithm is specified by selecting an algorithm number by an input unit. The selected tone synthesis algorithm is executed by a tone generator having a plurality of time-division multiplexed (TDM) modules for the synthesis of a tone.
With this arrangement, the user can select a tone synthesis algorithm but can not program it, i.e., assemble a connected structure of the plurality of tone generator modules. Further, with the increase of the number of tone synthesis algorithms, it becomes difficult for the user to grasp the correspondence between numbers and tone synthesis algorithms.
Further, the tone generator used in the above system is basically of the frequency modulation (FM) type. Therefore, the output of a module is usable in only two alternatives, one for partial output of the tone generator, and the other for part of a phase signal input to the same or a different module.
U.S. patent application Ser. No. 002,121, filed on Jan. 12, 1987, concerning the assignee of this application discloses a tone generator with a plurality of TDM modules, which can utilize the output of each module in various ways, for instance, as part of a synthesized tone, an envelope input to a different module or part thereof or a phase input to a different module or part thereof. Therefore, the number Of tone synthesis algOrithms executable by the tone generator is extremely large and may readily exceed 100,000 for eight modules. The application, however, does not show any technique that permits the user to select or assemble a tone synthesis algorithm.